The number of people giving up their US citizenship to become British has
surged thanks to complex tax rules introduced by the American tax
authorities.

London-based American lawyers, who specialise in tax and immigration, report a threefold increase over the last five years in the number of American citizens who are giving up their citizenship - a process known as “renunciation”.

Across the world 1,781 Americans renounced their citizenship in 2011 compared with just 231 in 2008, when US tax laws changed, although it remains unknown how many are adopting British rather than any other nationality.

Many decide to give up their American citizenship after tiring of the lengthy US tax return process, which requires them to pay tax on their total income regardless of where they live.

“There’s no question that the number of people renouncing their US citizenship is increasing,” said Diane Gelon, a US tax and immigration lawyer based in London.

“I probably get a dozen cases a year now when before 2008 when the tax laws changed it was just three or four.”

The process can be costly. Applicants must complete five years’ of US tax returns, which can cost £1,000 a year if professional help is obtained, plus another £2,500 for legal assistance with the immigration process, excluding VAT.

Even if a US citizen earns all their income in Britain they are liable for tax in their home country which can lead to unusual tax situations arising, said Ms Gelon.

For example, US citizens are expected to pay capital gains tax to the US government if they sell a property in Britain which is their main residence, even though a similar tax is not imposed by the British Inland Revenue.

The US rules make concessions for tax paid overseas but there is still a risk that their citizens will be hit with a large tax bill, she added.

“Actually giving up your citizenship is dead easy - once you have an appointment with a consular official it takes a matter of minutes.

“But getting an appointment in London can take three months and that is largely because of the tax issues,” she said.

“It can be an emotional thing, to give up one’s citizenship. I’ve had clients cancelling their appointments at the embassy on the day they were due to renounce because they just couldn’t go through with it.”

Susan McFadden, another London-based US attorney who specialises in immigration matters, said: “I’ve definitely seen a surge. In the last few years it’s gone up threefold and I see through about two dozen cases a year.

“The US Embassy in London has responded to that demand - and quite a long queue for renunciation appointments - by streamlining the process.

“We are told they have trained additional officers to reside over renunciation processes.”

The 2011 census found 177,185 people living in England and Wales were born in the US.

All American citizens are required to file a tax return on their world-wide income. The rule applies even if they have not visited the US for decades.

The US Internal Revenue Service is likely to discover tax returns have been missed in a number of different scenarios. For example, it may come to light if a citizen applies to renew a passport, is named as a beneficiary in a will or their foreign-based bank complies with new legislation which requires them to notify the US government about all American customers.

A US Embassy spokeswoman said: “US Embassy, London, can confirm that we process renunciations, provide information on renunciations on our website and are committed to providing good customer service to renunciants.”